[Info-vax] Another Alphaserver 1200 memory question

[Michael Moroney]

H Vlems <hvlems at freenet.de> writes:

>According to the Systems&Options guide the AlphaServer 1200 had three
>memory options: MS300-BA (64 MB), MS300-DA (256 MB) and the MS300-EA
>(512 MB).
>Now the -CA code is missing and I wondered whether two 64 MB boards
>would make a "mythical" MS300-CA.
>When added, SRM reported the two boards as a 32 MB memory option and
>that is what VMS also reported.
>I had expected to see the experiment fail, unable to complete T24, or
>unable to boot, or, since part of the console lives in upper memory, a
>spectacular crash when VMS boots.
>Who can supply an explanation for displaying only 25% of the installed
>memory pair?

Is what you have a "real" MS300-CA or just two 64 MB boards?  (does the 
-CA exist?)

The console code has to know of supported/possible memory combinations
so it can map them in place and locate the in-memory portion of the
console code.  It may not know of the 128MB combo because DEC never
planned to sell the -CA for it, and perhaps it just mapped it as a
default which happened to be 32MB.  (perhaps a -AA was planned, for NT
or something)